Extensible dome-form for cement cisterns.



No. 772,276. I

7 S.L.DUNLAP. 7 I EXTENSIBLE DOME FORM FOR CEMENT GISTERNS.

APPLICATION FILED NOV.12, 1903.

N0 MODEL.

PATENTED 007. 1 1904.

gluon/Mic:

\ v I sz'mayzL flun/Za UNITED STATES Y Patented October 11, 1904.

PATENT O FICE.

EXTENSIBLE DOME-FORM FOR CEMENT CISTERNS.

SPECIFICATION forming part of Letters Patent No. 772,276, dated October 11, 1904. Application filed November 12, 1903. Serial No. 180,828- (No model.)

To (LZZ whom, it may concern.-

Be it known that I, SIMON L. DUNLAP, a citizen of the United States. residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Extensible Dome- Forms for Cement Cisterns, of which the following is a specification.

This invention relates to devices for sup-. porting the necessary forms or'patterns in the construction of domes for cement cisterns, and is particularly adapted to be used in connection with that class of forms or patterns employed for constructing the side walls of cement cisterns as constitutes the subject matter of Letters Patent No. 695,804, issued to me and bearing date the 18th day of March, 1902.

The object of this invention consists in providing temporary supports to carry the segments in forming the domes of this class of cisterns, which supports are made extensible, sothat they can be readily adjusted to-fit the side-wall forms and may be varied to meet the various sizes of cisterns.

The object consists, further, in providing extensible temporary dome-forms which will be strong, durable, and which will be simple in construction, so that they can be easily placed into or removed from operative position after the cement has become sufficiently indurated.

Said invention consists in such construction and arrangement of parts of such a device whereby the various advantages sought are attained, and a device-embodying my said invention will now be fully described and the novel features thereof then pointed out in the claims.

Referring to the accompanying drawings, which are made a part hereof and on which similar numerals of reference indicate similar parts, Figure 1 is a top or plan view of one section of my extensible supports in operating position and shows the position occupied by the various segments that constitute the dome-patterns. Fig. 2 is a side elevation of the construction shown in Fig. 1. Fig. 3 is a fragmentary detail in side elevation and shows a modified construction of my tempo rary supports. Fig. 4 is a top or plan view of the construction shown in Fig. 3.

In the drawings, 1 represents the initial sections of my extensible supports, which consist, usually, of fiat bars bent in the shape of a letter V. Circular collars 2 are formed in the bars, from which the diverging arms extend. These collars rest against the collars 8, which are employed to form the manholes of the cisterns and which collars will be hereinafter described.

The outer ends of the bars 1 are bifurcated and terminate in the members 3. These members are bent at right angle to the main bodies of the bars and in oppositely-disposed directions, thence horizontally, thence downwardly to form the hooks 4L. The inclosures formed between the hooks and adjacent walls of the bars permit the insertion of the bars 5. The bars 5 provide the means for extending the supports and carry hooks, which are similar in both form and appearance to the hooks 1 on the bars 1. The hooks on the bars 5 embrace the bars 1. The hooks 4: on the bars 1 and 5 are so arranged to permit free longitudinal movement of the bars. The outer ends of the bars 5 are formed with notches 6, which engage with the tops of the side-wall forms employed in constructing the cistern-bodies and provide footings for the supports. The combined lengths of the bars 1 and 5 are suificient to span the radiuses of ordinary cisterns. When, however, a cistern of an'unusual size is desired, other sections of bars similar to the bars 5 may be added.

The bars 1 are also provided with set-screws 7, which bear against the surfaces of the bars 5, so that the two parts may be securely held when they have been extended to correspond with the radius of the proposed cistern.

In cistern construction provision is made to form the manholes when forming the domes. This is accomplished by means of the collars 8, heretofore referred to, which carry a plurality of screw-bolts 9. The collars 8 perform two functionsfirst, to outline the manholes, and, second, to form the support for the inner ends of the supports. Screw-bolts 9 pass through the collars 8 and through one side of the circular heads 2 of the bars 1 and rest against the internal side Walls of said heads. (See Fig. 1.) The bolts 9 provide the tension, which adds stability to the extensible supports and prevents them from shifting when in op erating position.

In Figs. 3 and 4 of the drawings I have shown in a modified form the manner in which the bars 1 and 5 may be adjustably secured together Without bifurcating the ends of the,

bars. In this instance the ends of the bars are bent in such a manner to form hooks which will embrace the bars when desired. This construction permits the bars to be entirely separated when out of use and also permits the formation of stronger hooks.

Having thus fully described my said invention, What I desire to secure by Letters Patent 1s- 1. In a device to support dome-forms for cement cisterns comprising a plurality of independent radially-formed initial sections, a plurality of members formed of the ends thereof and bent in hooks, bars engaging the hooks in the initial sections and terminating in a plurality of members which are bent in hooks,

the latter adapted to embrace the initial sec tions, means for rigidly securing the sections and bars together, in combination with a collar provided with screw-bolts that engage the initial sections, and the cistern-casing to form the support for the outer ends of the sections.

2. In a device to support dome-forms for cement cisterns comprising a plurality of independent sections, hooks formed in the ends of the sections, a plurality of extensible bars to engage and slide in the hooksjn the initial sections, hooks formed in the ends of the extensible bars which embrace the initial sections, in combination with a collar provided With screw-bolts that engage the initial sections, and the cistern-casing to support the outer ends of the sections.

In witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 7th day of November, A. D. 1903.

SIMON L. DUNLAP. [L. s.]

Witnesses:

F. W. VVOERNER, L. B. WOERNER. 

